Use of hydrogen peroxide for the chemical sterilization or disinfecting of soft contact lenses is well-known in the art. Such lenses are generally disinfected inside particularly-crafted contact lens holders. Hydrogen peroxide is an oxidative disinfectant which, as part of the disinfection process, breaks down into water and oxygen. For such disinfection systems, the container holding the lenses and the disinfectant must be designed to allow oxygen to escape to prevent excess buildup of vapor pressure and potential explosion or rupture of the container.
For example, U.S. Pat. No. 4,637,919 discloses a lens disinfecting container with a filter cartridge for use with oxidative disinfectants. This allows oxygen produced by decomposing hydrogen peroxide to escape from the device. Other attempts to solve this problem include U.S. Pat. No. 4,396,583 where a gas-permeable, liquid-impermeable membrane is loosely fitted inside a space in a cap of the device. The membrane is positioned between the disinfecting chamber and apertures located in the cap. The apertures in the cap allow gas which has passed through the membrane to escape.
Unfortunately, neither the '583 patent nor the '919 patent adequately solve the problem of venting the oxygen created during hydrogen peroxide decomposition while providing a leak-proof and non-clogging container. The '919 patent provides a container with minimal surface area to allow oxygen to escape. In addition, leakage is a potential problem as the filter cartridge is not adequately secured inside the aperture into which it is placed. Moreover, the filter cartridge would have a tendency to clog because of its minimal surface area. The '583 patent is also inadequate because it provides a membrane which can be easily dislodged so that the container is likely to leak.
There remains a need for a contact lens disinfecting container with a gas-permeable, liquid-impermeable member fixed securely thereto which can properly and adequately vent oxygen created during hydrogen peroxide decomposition without clogging or leaking.